Merge branch 'master' of github.com:kevinzhow/PNChart

@@ -11,7 +11,11 @@
 #import "PNChartLabel.h"
 #import "PNChartLabel.h"
 #import "PNBar.h"
 #import "PNBar.h"
 
 
-@interface PNBarChart()
+@interface PNBarChart() {
+    NSMutableArray* _bars;
+    NSMutableArray* _labels;
+}
+
 - (UIColor *)barColorAtIndex:(NSUInteger)index;
 - (UIColor *)barColorAtIndex:(NSUInteger)index;
 @end
 @end
 
 
@@ -26,6 +30,8 @@
         self.clipsToBounds   = YES;
         self.clipsToBounds   = YES;
         _showLabel           = YES;
         _showLabel           = YES;
         _barBackgroundColor  = PNLightGrey;
         _barBackgroundColor  = PNLightGrey;
+        _labels              = [NSMutableArray array];
+        _bars                = [NSMutableArray array];
     }
     }
 
 
     return self;
     return self;
@@ -62,6 +68,7 @@
 
 
 -(void)setXLabels:(NSArray *)xLabels
 -(void)setXLabels:(NSArray *)xLabels
 {
 {
+    [self viewCleanupForCollection:_labels];
     _xLabels = xLabels;
     _xLabels = xLabels;
 
 
     if (_showLabel) {
     if (_showLabel) {
@@ -73,6 +80,7 @@
             PNChartLabel * label = [[PNChartLabel alloc] initWithFrame:CGRectMake((index *  _xLabelWidth + chartMargin), self.frame.size.height - 30.0, _xLabelWidth, 20.0)];
             PNChartLabel * label = [[PNChartLabel alloc] initWithFrame:CGRectMake((index *  _xLabelWidth + chartMargin), self.frame.size.height - 30.0, _xLabelWidth, 20.0)];
             [label setTextAlignment:NSTextAlignmentCenter];
             [label setTextAlignment:NSTextAlignmentCenter];
             label.text = labelText;
             label.text = labelText;
+            [_labels addObject:label];
             [self addSubview:label];
             [self addSubview:label];
         }
         }
     }
     }
@@ -86,7 +94,7 @@
 
 
 -(void)strokeChart
 -(void)strokeChart
 {
 {
-
+    [self viewCleanupForCollection:_bars];
     CGFloat chartCavanHeight = self.frame.size.height - chartMargin * 2 - 40.0;
     CGFloat chartCavanHeight = self.frame.size.height - chartMargin * 2 - 40.0;
     NSInteger index = 0;
     NSInteger index = 0;
 
 
@@ -103,12 +111,21 @@
         bar.backgroundColor = _barBackgroundColor;
         bar.backgroundColor = _barBackgroundColor;
         bar.barColor = [self barColorAtIndex:index];
         bar.barColor = [self barColorAtIndex:index];
         bar.grade = grade;
         bar.grade = grade;
+        [_bars addObject:bar];
         [self addSubview:bar];
         [self addSubview:bar];
 
 
         index += 1;
         index += 1;
     }
     }
 }
 }
 
 
+- (void)viewCleanupForCollection:(NSMutableArray*)array
+{
+    if (array.count) {
+        [array makeObjectsPerformSelector:@selector(removeFromSuperview)];
+        [array removeAllObjects];
+    }
+}
+
 #pragma mark - Class extension methods
 #pragma mark - Class extension methods
 
 
 - (UIColor *)barColorAtIndex:(NSUInteger)index
 - (UIColor *)barColorAtIndex:(NSUInteger)index